/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.io;

import proguard.classfile.*;
import proguard.classfile.util.ClassUtil;

import java.io.*;
import java.util.Map;

/**
 * This DataEntryWriter delegates to another DataEntryWriter, renaming the data entries based on the renamed classes in
 * the given ClassPool.
 *
 * @author Eric Lafortune
 */
public class RenamedDataEntryWriter implements DataEntryWriter {
    private final ClassPool classPool;
    private final Map packagePrefixMap;
    private final DataEntryWriter dataEntryWriter;

    /**
     * Creates a new RenamedDataEntryWriter.
     * 
     * @param classPool the class pool that maps from old names to new names.
     * @param packagePrefixMap the map from old package prefixes to new package prefixes.
     * @param dataEntryWriter the DataEntryWriter to which calls will be delegated.
     */
    public RenamedDataEntryWriter(ClassPool classPool, Map packagePrefixMap, DataEntryWriter dataEntryWriter) {
        this.classPool = classPool;
        this.packagePrefixMap = packagePrefixMap;
        this.dataEntryWriter = dataEntryWriter;
    }

    // Implementations for DataEntryWriter.

    public boolean createDirectory(DataEntry dataEntry) throws IOException {
        return dataEntryWriter.createDirectory(renamedDataEntry(dataEntry));
    }

    public boolean sameOutputStream(DataEntry dataEntry1, DataEntry dataEntry2) throws IOException {
        return dataEntryWriter.sameOutputStream(dataEntry1, dataEntry2);
    }

    public OutputStream createOutputStream(DataEntry dataEntry) throws IOException {
        return dataEntryWriter.createOutputStream(renamedDataEntry(dataEntry));
    }

    public void close() throws IOException {
        dataEntryWriter.close();
    }

    public void println(PrintWriter pw, String prefix) {
        dataEntryWriter.println(pw, prefix);
    }

    // Small utility methods.

    /**
     * Create a renamed data entry, if possible.
     */
    private DataEntry renamedDataEntry(DataEntry dataEntry) {
        String dataEntryName = dataEntry.getName();

        // Try to find a corresponding class name by removing increasingly
        // long suffixes.
        for (int suffixIndex = dataEntryName.length() - 1; suffixIndex > 0; suffixIndex--) {
            char c = dataEntryName.charAt(suffixIndex);
            if (!Character.isLetterOrDigit(c)) {
                // Chop off the suffix.
                String className = dataEntryName.substring(0, suffixIndex);

                // Did we get to the package separator?
                if (c == ClassConstants.PACKAGE_SEPARATOR) {
                    break;
                }

                // Is there a class corresponding to the data entry?
                Clazz clazz = classPool.getClass(className);
                if (clazz != null) {
                    // Did the class get a new name?
                    String newClassName = clazz.getName();
                    if (!className.equals(newClassName)) {
                        // Return a renamed data entry.
                        String newDataEntryName = newClassName + dataEntryName.substring(suffixIndex);

                        return new RenamedDataEntry(dataEntry, newDataEntryName);
                    } else {
                        // Otherwise stop looking.
                        return dataEntry;
                    }
                }
            }
        }

        // Try to find a corresponding package name by increasingly removing
        // more subpackages.
        String packagePrefix = dataEntryName;
        do {
            // Chop off the class name or the last subpackage name.
            packagePrefix = ClassUtil.internalPackagePrefix(packagePrefix);

            // Is there a package corresponding to the package prefix?
            String newPackagePrefix = (String)packagePrefixMap.get(packagePrefix);
            if (newPackagePrefix != null) {
                // Did the package get a new name?
                if (!packagePrefix.equals(newPackagePrefix)) {
                    // Return a renamed data entry.
                    String newDataEntryName = newPackagePrefix + dataEntryName.substring(packagePrefix.length());

                    return new RenamedDataEntry(dataEntry, newDataEntryName);
                } else {
                    // Otherwise stop looking.
                    return dataEntry;
                }
            }
        } while (packagePrefix.length() > 0);

        return dataEntry;
    }
}
